For modern Radio Access Technologies (RATs), transceivers need to support standards with a huge variety of different bandwidths. For example, Narrow Band—Long Term Evolution (NB-LTE) for cellular Internet of Things (IoT) applications specifies a bandwidth of 180 kHz, wherein a further reduction of the bandwidth down to 15 kHz is discussed. On the other side, LTE20 specifies carrier aggregation with a bandwidth of 40 MHz, Wireless Local Area Networks (WLANs) use a bandwidth of 160 MHz, and 5th generation mobile networks (i.e. 5G) are specified for bandwidths of 100 MHz and more.
In principal, digital complexity of the transmitter and, hence, current consumption of the digital transmitter part increases with the bandwidth that is to be transmitted. For example, an LTE20 signal with 100 allocated Physical Resource Blocks (PRBs) requires an about 100 times higher complexity of the digital part/current consumption in the digital part of a transmitter compared to a transmitter optimized for one allocated PRB.
For each transmit band, different masks need to be fulfilled by the transmitter. Some of the masks are easier to fulfill than others. Moreover, the transmitter transmits its output signals with different output power.
Hence, there may be a desire for a transmitter architecture that allows for reduced current consumption.